python第一周练习 货币转换

TempStr=input()
if TempStr[0:3] in ['RMB']:
    c=eval(TempStr[3:])/6.78
    print('USD{:.2f}'.format(c))
elif TempStr[0:3] in ['USD']:
    b=eval(TempStr[3:])*6.78
    print('RMB{:.2f}'.format(b))
else:
    pass